It also says that the actual phone functionality doesn't work on that image (an area where the CDMA version differs from the original GSM one). More information can be found in the forum thread on XDA Developers:

Unfortunately the link for the device specific zip is down, so that answer is not usable at the moment
–
sbergeronJul 7 '14 at 20:01

I'm not sure whether it is worth trying to get it running on this hardware any more anyway. The GSM Galaxy Nexus is no longer supported for development (it's GPU is significantly less capable than the others).
–
James HenstridgeJul 7 '14 at 23:47

an old phone is still worth it, when the latest and greatest can't run great on it I thought that was exactly what ubuntu was for, for machines that either you like ubuntu on or that don't run the latest software. Just dropping support for a device that still functions seems foolhardy and somewhat against the main goal of ubuntu, an os for every computer
–
sbergeronJul 8 '14 at 0:19

The current set of supported devices represent what we have been using for development. The end goal is to make phones with Ubuntu preinstalled available to end users, rather than having them buy Android phones and reflash them. Here's the message about EOL'ing the Galaxy Nexus: lists.launchpad.net/ubuntu-phone/msg05889.html
–
James HenstridgeJul 8 '14 at 2:22